Resetting spacer lift to stock?

What up TWM's. Currently I have a spacer lift in the front and blocks in the back and would like to set everything back to stock. I am ordering the 5100's/5125's kit and would like to know if I'll be needing some oem parts in order to complete this job correctly. It also has differential drop spacers. Does that mean I will need shorter bolt's, it seems logical but I really have no clue. I bought the truck like this so I don't know what was done. Perhaps it would be easier if someone took a look unless any of you have done something like this before. Any info on this would be much appreciated thank you.